Hello:
Your turntable is a good, "consumer-grade" unit, made by an old,
well-respected company. (I once saw a Victrola that had been fitted with a
Thorens
reproducer.) However, like most newer turntables, they are optimized for vinyl
playback, with shellac 78 playback capabilities sort of grafted onto them.
A lot of semiautomatic turntables have a "manual" mode, which requires the
operator to lift the tone arm at the end of the record. I think the newer
version TD-170 turntables have this feature. If your turntable does have this
feature, using it might be the simplest answer to your problem.
It is hard to say more, based on the limited information you supply. How old
are the "78's" you are trying to play? Do they have eccentric grooves at the
end of the selections, which are designed to trigger the auto-stop feature?
If not, the records are probably pretty old, and the auto-stop issue is not
your only problem. Proper playback speeds, tracking angles, and styli all
need
to be determined, if you are playing 78's made before World War II.
Good Luck,
Randy